The antioxidant properties of substituted diarylamines in the benzo[b]thiophene series were evaluated by their reducing
power and free radical scavenging activity. The results were compared with those of standards: acid ascorbic for the first method and
BHA and BHT for the second. For both methods it was possible to establish some structure–activity relationships (SARs) based on
the position of the arylamination on the benzo[b]thiophene moiety, the presence of different substituents on the phenyl ring (F, 1 or 2
OMe) and on the thiophene ring (H, CO2Et, CO2H).